1. Field of the Invention
The present invention relates to a method of manufacturing a water repellent film and a thereby manufactured water repellent film, and more particularly to a method of manufacturing a water repellent film by means of vapor phase deposition and a thereby manufactured water repellent film.
2. Description of the Related Art
An inkjet head used in an inkjet recording apparatus has a nozzle plate formed with nozzles, through which droplets of ink are ejected and deposited onto a recording medium to form an image on the recording medium. If the ink has adhered to a surface of the nozzle plate (hereinafter referred also to as a “nozzle face”), the adhering ink affects droplets of the ink ejected through the nearby nozzle, and deviations may occur in ejection directions of the ink droplets. Thus, in the state where the ink has adhered to the nozzle face, it is difficult to deposit the ink droplets at prescribed positions on the recording medium and this causes deterioration of the formed image.
Therefore, in order to prevent ink adhering to the surface of the nozzle plate and to thereby improve ejection properties of the inkjet head, it has been proposed to form a water repellent film on the surface of the nozzle plate.
A water repellent coating of a silane coupling agent is known as a high-adhesive water repellent film. Conventionally, the method generally used to form the water repellent film of the silane coupling agent is a dipping method, in which a silane coupling material is dissolved in a fluoric solvent while adjusting the concentration thereof to about 0.1 wt %, and a substrate is immersed in this solution and then drawn out and dried.
However, in recent years, there have been many cases where it has not been possible to immerse substrates in the solution in order to form the water repellent films, because the substrates on which the water repellent films are to be formed have no resistance to the solvent used. In these cases, the silane coupling material is applied to the substrates to form the films by means of a gas phase method (vapor phase deposition method).
For example, Japanese Patent Application Publication Nos. 2006-291266, 2007-533448, 2000-328230 and 2009-220396 describe methods of forming films of fluoric water repellent materials by means of vapor phase deposition.
Furthermore, the nozzle face of the inkjet head needs to be wiped to maintain ejection stability of the inkjet head. There is a problem in that if an excessive amount of water repellent material has been deposited on the nozzle face, the surplus water repellent material is liable to be removed when the nozzle face is rubbed by wiping, and the like, and then the removed material blocks the nozzles. Therefore, Japanese Patent Application Publication No. 2009-220396 describes that recess sections are formed on the nozzle face so that surplus water repellent material collects in the recess sections, thereby preventing blockage of the interior of the nozzles. Japanese Patent Application Publication No. 2005-262471 describes that water repellent material having weak bonds is beforehand removed by means of an adhesive tape.